• Proceedings of the KIEE Conference
• /
• 1997.07d
• /
• pp.1267-1269
• /
• 1997

본 논문에서는 SDB(Silicon Direct Bonding) 기술을 적용하여 빠른 스위칭 속도 및 낮은 도통 전압을 갖는 1200v 10A n-ch IGBT를 제작하였다. 기존의 epi wafer를 이용한 IGBT 제작시 스위칭 속도 개선을 위한 전자조사 방법을 사용하지 않고 buffer의 농도를 증가시켜 아노드 영역의 정공 주입 효율을 제어하여 90ns의 스위칭 속도를 가지며, 2.0V의 도통전압을 갖는 IGBT를 구현하였으며, SDB IGBT 제작시 bonding 계면의 문제 및 표면의 particle 및 결함이 소자의 전기적 특성에 미치는 영향을 고찰하였으며, 이를 실험 결과와 비교 평가하였다.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.3 s.96
• /
• pp.78-83
• /
• 1999

The bonding interface is dependent on the properties of surfaces prior to SDB(silicon wafer direct bonding). In this paper, we prepared silicon surfaces in several chemical solutions, and annealed bonding wafers which were combined with thermally oxidized wafers and bare silicon wafers in the temperature range of $600{\times}1000^{\circ}C$. After bonding, the bonding interface is investigated by an infrared(IR) topography system which uses the penetrability of infrared through silicon wafer. Using this procedure, we observed intrinsic bubbles at elevated temperatures. So, we verified that these bubbles are related to cleaning and drying conditions, and the interface oxides on silicon wafer reduce the formation of intrinsic bubbles.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.6
• /
• pp.305-310
• /
• 2013

In this paper, the pressure sensor usable in a high temperature, using a SDB(silicon-direct-bonding) wafer of Si/$SiO_2$/Si-sub structure was provided and studied the characteristic thereof. The pressure sensor produces a piezoresistor by using a single crystal silicon as a first layer of SDB wafer, to thus provide a prominent sensitivity, and dielectrically isolates the piezoresistor from a silicon substrate by using a silicon dioxide layer as a second layer thereof, to be thus usable even under the high temperature over $120^{\circ}C$ as a limited temperature of a general silicon sensor. The measured result for a pressure sensitivity of the pressure sensor has a characteristic of high sensitivity, and its tested result for an output of the sensor further has a very prominent linearity and hysteresis characteristic.

• Journal of Sensor Science and Technology
• /
• v.3 no.2
• /
• pp.74-80
• /
• 1994

Silicon direct bonding technology is very attractive for both silicon-on-insulator devices and sensor fabrication because of its thermal stress free structure and stability. The process of SDB includes hydration of silicon wafer and heat treatment in a wet oxidation furnace. After hydration process, hydroxyl groups of silicon wafer were analyzed by using Fourier transformation-infrared spectroscopy. In case of hydrophilic treatment using a ($H_{2}O_{2}\;:\;H_{2}SO_{4}$) solution, hydroxyl groups are observed in a broad band around the 3474 $cm^{-1}$ region. However, hydroxyl groups do not appear in case of diluted HF solution. The bonded wafer was etched by using tetramethylammonium hydroxide etchant. The surface of the self etch-stopped silicon dioxide is completely flat, so that it can be used as sensor applications such as pressure, flow and acceleration, etc..

• Korean Journal of Materials Research
• /
• v.11 no.3
• /
• pp.159-163
• /
• 2001

The success of SDB (silicon wafer direct bonding) technology can be estabilished by bonding on the bonded interface with no defects and Preventing temperature dependent bubbles. In this research, we observed the behavior of the intrinsic bubbles by transmitting the infrared light and the increase of the bubble pressure was found. And, the $SiO_2$-$SiO_2$ bonded wafer was achieved, which generates no intrinsic bubbles in the annealing under the atmospheric pressure. The intrinsic bubbles in the $SiO_2$-$SiO_2$ bonded wafer were generated in the annealing in the ultra high vacuum. This experimental result shows the relation between the bubble growth and the pressure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.759-762
• /
• 2000

Present transistors which have vertical structure show increased parasitic capacitance characteristics in accordance with the increase of non-active base area and collector area, consequently have disadvantage for high speed switching performance. In this paper, a horizontal structure transistor which has minimized parasitic capacitance in virtue of SDB(Silicon Direct Bonding) wafer and oxide sidewall isolation utilizing silicon trench technology is presented. Its structural characteristics were designed by ATHENA(SUPREM4), the process simulator from SILVACO International, and its performance was proven by ATLAS, the device simulator from SILVACO International. The performance of the proposed horizontal structure transistor was certified through the VCE-lC characteristics curve, $h_{FE}$ -IC characteristics, and GP-plot.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07b
• /
• pp.830-833
• /
• 2003

This paper describes the fabrication and characteristics of 3C-SiCOI sotctures by SDB and etch-back technology for high-temperature MEMS applications. In this work, insulator layers were formed on a heteroepitaxial 3C-SiC film grown on a Si(001) wafer by thermal wet oxidation and PECVD process, successively. The pre-bonding of two polished PECVD oxide layers made the surface activation in HF and bonded under applied pressure. The wafer bonding characteristics were evaluated by the effect of HF concentration used in the surface treatment on the roughness of the oxide and pre-bonding strength. Hydrophilic character of the oxidized 3C-SiC film surface was investigated by ATR-FTIR. The strength of the bond was measured by tensile strengthmeter. The bonded interface was also analyzed by SEM. The properties of fabricated 3C-SiCOI structures using etch-back technology in TMAH solution were analyzed by XRD and SEM. These results indicate that the 3C-SiCOI structure will offers significant advantages in the high-temperature MEMS applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07a
• /
• pp.147-150
• /
• 2003

In this paper, We fabricated a high temperature pressure sensor using SBD(silicon- direct-bonding) wafer of $Si/SiO_2$/Si-sub structure. This sensor was very sensitive because the piezoresistor is fabricated by single crystal silicon of the first layer of SDB wafer. Also, it was possible to operate the sensor at high temperature over $120^{\circ}C$ which is the temperature limitation of general silicon sensor because the piezoresistor was dielectric isolation from silicon substrate using silicon dioxide of the second layer. The sensitivity of this sensor is very high as the measured result of D2200 shows $183.6\;{\mu}V/V{\cdot}kPa$. Also, the output characteristic of linearity was very good. This sensor was available at high temperature as $300^{\circ}C$.

• Journal of Sensor Science and Technology
• /
• v.13 no.3
• /
• pp.175-181
• /
• 2004

A pressure sensor for high temperature was fabricated by using a SDB(Silicon-Direct-Bonding) wafer with a Si/$SiO_{2}$/ Si structure. High pressure sensitivity was shown from the sensor using a single crystal silicon of the first layer as a piezoresistive layer. It also was made feasible to use under the high temperature as of over $120^{\circ}C$, which is generally known as the critical temperature for the general silicon sensor, by isolating the piezoresistive layer dielectrically and thermally from the silicon substrate with a silicon dioxide layer of the second layer. The pressure sensor fabricated in this research showed very high sensitivity as of $183.6{\mu}V/V{\cdot}kPa$, and its characteristics also showed an excellent linearity with low hysteresis. This sensor was usable up to the high temperature range of $300^{\circ}C$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.6
• /
• pp.514-519
• /
• 2000

This paper describes on the temperature characteristics of a SDB(silicon-wafer direct bonding) SOI(silicon-on-insulator) Hall sensor. Using the buried oxide $SiO_2$as a dielectrical isolation layer a SDB SOI Hall sensor without pn junction has been fabricated on the Si/ $SiO_2$/Si structure. The Hall voltage and the sensitivity of the implemented SOI Hall sensor show good linearity with respect to the applied magnetic flux density and supplied current. In the temperature range of 25 to 30$0^{\circ}C$ the shifts of TCO(temperature coefficient of the offset voltage) and TCS(temperature coefficient of the product sensitivity) are less than $\pm$6.7$\times$10$_{-3}$ and $\pm$8.2$\times$10$_{-4}$$^{\circ}C$ respectively. These results indicate that the SDB SOI structure has potential for the development of a silicon Hall sensor with a high-sensitivity and high-temperature operation.